Gamma-ray Burst 191001B

(All information courtesy of the instrument teams.)

Previous IAU Circulars

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Results of Observations

GCN/BACODINE POSITION NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 01 Oct 19 17:21:09 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     927345,   Seg_Num: 0
GRB_RA:           86.368d {+05h 45m 28s} (J2000),
                  86.590d {+05h 46m 22s} (current),
                  85.807d {+05h 43m 14s} (1950)
GRB_DEC:         -15.907d {-15d 54' 25"} (J2000),
                 -15.900d {-15d 54' 00"} (current),
                 -15.926d {-15d 55' 33"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       0 [cnts]    Image_Peak=2353 [image_cnts]
TRIGGER_DUR:     80.000 [sec] 
TRIGGER_INDEX:   20000     E_range: 15-50 keV
BKG_INTEN:       0 [cnts]
BKG_TIME:        0.00 SOD {00:00:00.00} UT
BKG_DUR:         0 [sec]
GRB_DATE:        18757 TJD;   274 DOY;   19/10/01
GRB_TIME:        62360.32 SOD {17:19:20.32} UT
GRB_PHI:           9.20 [deg]
GRB_THETA:        45.70 [deg]
SOLN_STATUS:     0x13
RATE_SIGNIF:     0.00 [sigma]
IMAGE_SIGNIF:    14.15 [sigma]
MERIT_PARAMS:     +1  +0  +0  +6  +1  +3  +0  +0 +16  +0 
SUN_POSTN:       187.57d {+12h 30m 18s}   -3.27d {-03d 16' 09"}
SUN_DIST:         99.63 [deg]   Sun_angle= 6.7 [hr] (West of Sun)
MOON_POSTN:      227.78d {+15h 11m 06s}  -13.55d {-13d 32' 56"}
MOON_DIST:       131.63 [deg]
MOON_ILLUM:      12 [%]
GAL_COORDS:      220.31,-21.59 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       85.49,-39.29 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        SWIFT-BAT GRB Coordinates.  
COMMENTS:        This is an image trigger.  (The RATE_SIGNIF & BKG_{INTEN, TIME, DUR} are undefined.)  
COMMENTS:        A point_source was found.  
COMMENTS:        This does not match any source in the on-board catalog.  
COMMENTS:        This does not match any source in the ground catalog.  
COMMENTS:        This is a GRB.  
COMMENTS:        This trigger occurred at longitude,latitude = 242.76,19.44 [deg].

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 01 Oct 19 17:27:44 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve 
TRIGGER_NUM:     131095,   Seg_Num: 0
GRB_RA:           86.368d {+05h 45m 28s} (J2000),
                  86.590d {+05h 46m 22s} (current),
                  85.807d {+05h 43m 14s} (1950)
GRB_DEC:         -15.907d {-15d 54' 25"} (J2000),
                 -15.900d {-15d 54' 00"} (current),
                 -15.926d {-15d 55' 33"} (1950)
GRB_DATE:        18757 TJD;   274 DOY;   19/10/01
GRB_TIME:        62360.32 SOD {17:19:20.32} UT
TRIGGER_INDEX:   20000
GRB_PHI:           9.20 [deg]
GRB_THETA:        45.70 [deg]
DELTA_TIME:      0.00 [sec]  
TRIGGER_DUR:     80.000 [sec]  
SOLN_STATUS:     0x13
RATE_SIGNIF:     0.00 [sigma]
IMAGE_SIGNIF:    0.00 [sigma]
LC_URL:          sw00927345000msb.lc
SUN_POSTN:       187.58d {+12h 30m 19s}   -3.27d {-03d 16' 16"}
SUN_DIST:         99.64 [deg]   Sun_angle= 6.7 [hr] (West of Sun)
MOON_POSTN:      227.84d {+15h 11m 21s}  -13.57d {-13d 34' 10"}  
MOON_DIST:       131.67 [deg] 
MOON_ILLUM:      12 [%] 
GAL_COORDS:      220.31,-21.59 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       85.49,-39.29 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        SWIFT-BAT GRB Lightcurve.
COMMENTS: 
COMMENTS:        WARNING: No BAT_Position TDRSS message was received for this trigger_number! 
COMMENTS:     
COMMENTS:     
COMMENTS:        The next comments were copied from the BAT_POS Notice:
COMMENTS:        This is an image trigger.
COMMENTS:        A point_source was found.
COMMENTS:        This does not match any source in the on-board catalog.
COMMENTS:        This does not match any source in the ground catalog.
COMMENTS:        This is a GRB. 
COMMENTS:        This trigger occurred at longitude,latitude = 242.76,19.44 [deg].
COMMENTS:        The 3rd packet (of 3) was missing in the lightcurve data stream.

GCN Circular #25902
E. Troja (NASA/GSFC/UMCP), E. Ambrosi (INAF-IASFPA), S. D. Barthelmy (GSFC), V. D'Elia (SSDC), J. A. Kennea (PSU), N. J. Klingler (PSU), F. E. Marshall (NASA/GSFC), M. J. Moss (GWU), B. Sbarufatti (PSU) and A. Tohuvavohu (Toronto) report on behalf of the Neil Gehrels Swift Observatory Team:
At 17:19:20 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 191001B (trigger=927345). Swift did not slew due to targets with higher priority. The BAT on-board calculated location is RA, Dec 86.368, -15.907 which is
```
   RA(J2000)  =  05h 45m 28s
   Dec(J2000) = -15d 54' 25"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve shows several peaks with a total duration of about 25 sec. The peak count rate was ~1600 counts/sec (15-350 keV), at ~20 sec after the trigger.
Due to higher priority observations, Swift will not slew to the BAT position. There will thus be no prompt XRT or UVOT data for this trigger.
Burst Advocate for this burst is E. Troja (eleonora.troja AT nasa.gov). Please contact the BA by email if you require additional information regarding Swift followup of this burst. In extremely urgent cases, after trying the Burst Advocate, you can contact the Swift PI by phone (see Swift TOO web site for information: http://www.swift.psu.edu/)
GCN Circular #25906
K. L. Murata, R. Adachi, M. Oeda, K.Shiraishi, K. Iida, M. Niwano, F. Ogawa, R. Hosokawa, S. Toma, Y. Yatsu, and N. Kawai (TokyoTech) report on behalf of the MITSuME collaboration:
We searched for the optical counterpart of GRB 191001B (E. Troja et al., GCN Circular #25902) with the optical three color (g', Rc, and Ic) CCD cameras attached to the MITSuME 50 cm telescope of Akeno Observatory, Yamanashi, Japan.
The observation started on 17:22:09 UT. We did not find any new point sources within the BAT on-board calculated error circle in all three bands. We obtained the following 5-sigma limits for the magnitudes.
```
T0+[sec]   MID-UT    T-EXP[sec]    5-sigma limits
--------------------------------------------------------------------------------------
+----------
~169       ~17:37    1680             g'>18.8, Rc>18.8, Ic>18.6
--------------------------------------------------------------------------------------
+----------
T0+ : Elapsed time after the burst
T-EXP: Total Exposure time
```
We used GSC2.3 catalog for flux calibration. The magnitudes are expressed in the AB system.
GCN Circular #25930
D. M. Palmer (LANL), S. D. Barthelmy (GSFC), J. R. Cummings (CPI), H. A. Krimm (NSF), S. Laha (GSFC/UMBC), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), T. Sakamoto (AGU), M. Stamatikos (OSU), E. Troja (NASA/GSFC/UMCP), T. N. Ukwatta (LANL) (i.e. the Swift-BAT team):
Using the data set from T-239 to T+962 sec from the recent telemetry downlink, we report further analysis of BAT GRB 191001B (trigger #927345) (Troja et al., GCN Circ. 25902). The BAT ground-calculated position is RA, Dec = 86.423, -15.880 deg which is
```
   RA(J2000)  =  05h 45m 41.5s
   Dec(J2000) = -15d 52' 48.3"
```
with an uncertainty of 3.6 arcmin, (radius, sys+stat, 90% containment). The partial coding was 33%.
The mask-weighted light curve shows a multi-peaked structure that starts at ~T-10 s and ends at ~T+130 s. T90 (15-350 keV) is 108.9 +- 15.1 sec (estimated error including systematics).
The time-averaged spectrum from T-8.77 to T+126.11 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.58 +- 0.11. The fluence in the 15-150 keV band is 4.6 +- 0.3 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T+20.44 sec in the 15-150 keV band is 1.8 +- 0.4 ph/cm2/sec. All the quoted errors are at the 90% confidence level.
The results of the batgrbproduct analysis are available at http://gcn.gsfc.nasa.gov/notices_s/927345/BA/
GCN Circular #25940
R. Strausbaugh (U. of the Virgin Islands), A. Cucchiara (U. of the Virgin Islands/College of Marin) report on behalf of a larger collaboration:
We observed Swift GRB 191001B (Barthelmy et al., GCN 25902) with the LCO 1-m Sinistro instrument on October 2, from 01:23 to 01:47 UT (corresponding to 5.73 to 6.2 hours from the GRB trigger time) with the SDSS r’ and i’ filters.
We performed a series of 5x120s exposures in each band. We do not detect any fading sources over the course of our observations in a 26.5' x 26.5' field of view centered around the Swift coordinates (Barthelmy et al., GCN 25902). Using the USNO-B.1 catalog as reference, we obtain the following 3-sigma upper limits:
r > 18.82
i > 16.98
These observations were possible thanks to the USVI NASA-EPSCoR Research Infrastructure Development (RID) grant NNX16AL44A.

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Jochen Greiner, last update: 03-Oct-2019 [Disclaimer]